Auto merge of #46574 - GuillaumeGomez:rollup, r=GuillaumeGomez

Rollup of 5 pull requests

- Successful merges: #46416, #46444, #46526, #46539, #46548
- Failed merges:

10 files changed, 206 insertions, 40 deletions

diff --git a/.gitattributes b/.gitattributes
index e737c7946ef..2b4f3d47263 100644
--- a/.gitattributes
+++ b/.gitattributes
@@ -7,3 +7,4 @@
 src/etc/installer/gfx/* binary
 *.woff binary
 src/vendor/** -text
+Cargo.lock -merge
diff --git a/src/libcore/macros.rs b/src/libcore/macros.rs
index fe2df226115..948ad104cdf 100644
--- a/src/libcore/macros.rs
+++ b/src/libcore/macros.rs
@@ -736,7 +736,7 @@ mod builtin {
     #[cfg(dox)]
     macro_rules! module_path { () => ({ /* compiler built-in */ }) }
 
-    /// Boolean evaluation of configuration flags.
+    /// Boolean evaluation of configuration flags, at compile-time.
     ///
     /// For more information, see the documentation for [`std::cfg!`].
     ///
diff --git a/src/libcore/option.rs b/src/libcore/option.rs
index 12e6e843056..d8f3ec38cf3 100644
--- a/src/libcore/option.rs
+++ b/src/libcore/option.rs
@@ -338,6 +338,12 @@ impl<T> Option<T> {
 
     /// Returns the contained value or a default.
     ///
+    /// Arguments passed to `unwrap_or` are eagerly evaluated; if you are passing
+    /// the result of a function call, it is recommended to use [`unwrap_or_else`],
+    /// which is lazily evaluated.
+    ///
+    /// [`unwrap_or_else`]: #method.unwrap_or_else
+    ///
     /// # Examples
     ///
     /// ```
@@ -451,11 +457,16 @@ impl<T> Option<T> {
     /// Transforms the `Option<T>` into a [`Result<T, E>`], mapping [`Some(v)`] to
     /// [`Ok(v)`] and [`None`] to [`Err(err)`].
     ///
+    /// Arguments passed to `ok_or` are eagerly evaluated; if you are passing the
+    /// result of a function call, it is recommended to use [`ok_or_else`], which is
+    /// lazily evaluated.
+    ///
     /// [`Result<T, E>`]: ../../std/result/enum.Result.html
     /// [`Ok(v)`]: ../../std/result/enum.Result.html#variant.Ok
     /// [`Err(err)`]: ../../std/result/enum.Result.html#variant.Err
     /// [`None`]: #variant.None
     /// [`Some(v)`]: #variant.Some
+    /// [`ok_or_else`]: #method.ok_or_else
     ///
     /// # Examples
     ///
@@ -644,6 +655,12 @@ impl<T> Option<T> {
 
     /// Returns the option if it contains a value, otherwise returns `optb`.
     ///
+    /// Arguments passed to `or` are eagerly evaluated; if you are passing the
+    /// result of a function call, it is recommended to use [`or_else`], which is
+    /// lazily evaluated.
+    ///
+    /// [`or_else`]: #method.or_else
+    ///
     /// # Examples
     ///
     /// ```
diff --git a/src/libcore/result.rs b/src/libcore/result.rs
index 959935242dc..2ace3d2aee8 100644
--- a/src/libcore/result.rs
+++ b/src/libcore/result.rs
@@ -625,8 +625,13 @@ impl<T, E> Result<T, E> {
 
     /// Returns `res` if the result is [`Err`], otherwise returns the [`Ok`] value of `self`.
     ///
+    /// Arguments passed to `or` are eagerly evaluated; if you are passing the
+    /// result of a function call, it is recommended to use [`or_else`], which is
+    /// lazily evaluated.
+    ///
     /// [`Ok`]: enum.Result.html#variant.Ok
     /// [`Err`]: enum.Result.html#variant.Err
+    /// [`or_else`]: #method.or_else
     ///
     /// # Examples
     ///
@@ -690,8 +695,13 @@ impl<T, E> Result<T, E> {
     /// Unwraps a result, yielding the content of an [`Ok`].
     /// Else, it returns `optb`.
     ///
+    /// Arguments passed to `unwrap_or` are eagerly evaluated; if you are passing
+    /// the result of a function call, it is recommended to use [`unwrap_or_else`],
+    /// which is lazily evaluated.
+    ///
     /// [`Ok`]: enum.Result.html#variant.Ok
     /// [`Err`]: enum.Result.html#variant.Err
+    /// [`unwrap_or_else`]: #method.unwrap_or_else
     ///
     /// # Examples
     ///
diff --git a/src/librustdoc/html/layout.rs b/src/librustdoc/html/layout.rs
index 8c14d1bbe8f..61de5f4bc4c 100644
--- a/src/librustdoc/html/layout.rs
+++ b/src/librustdoc/html/layout.rs
@@ -65,6 +65,7 @@ r##"<!DOCTYPE html>
     {before_content}
 
     <nav class="sidebar">
+        <div class="sidebar-menu">&#9776;</div>
         {logo}
         {sidebar}
     </nav>
diff --git a/src/librustdoc/html/render.rs b/src/librustdoc/html/render.rs
index 9dc01bb0916..d42faebd39e 100644
--- a/src/librustdoc/html/render.rs
+++ b/src/librustdoc/html/render.rs
@@ -3542,6 +3542,7 @@ impl<'a> fmt::Display for Sidebar<'a> {
         let cx = self.cx;
         let it = self.item;
         let parentlen = cx.current.len() - if it.is_mod() {1} else {0};
+        let mut should_close = false;
 
         if it.is_struct() || it.is_trait() || it.is_primitive() || it.is_union()
             || it.is_enum() || it.is_mod() || it.is_typedef()
@@ -3575,6 +3576,8 @@ impl<'a> fmt::Display for Sidebar<'a> {
                 }
             }
 
+            write!(fmt, "<div class=\"sidebar-elems\">")?;
+            should_close = true;
             match it.inner {
                 clean::StructItem(ref s) => sidebar_struct(fmt, it, s)?,
                 clean::TraitItem(ref t) => sidebar_trait(fmt, it, t)?,
@@ -3625,6 +3628,10 @@ impl<'a> fmt::Display for Sidebar<'a> {
             write!(fmt, "<script defer src=\"{path}sidebar-items.js\"></script>",
                    path = relpath)?;
         }
+        if should_close {
+            // Closes sidebar-elems div.
+            write!(fmt, "</div>")?;
+        }
 
         Ok(())
     }
diff --git a/src/librustdoc/html/static/main.js b/src/librustdoc/html/static/main.js
index bdd7b7dd0b7..06e9cbbdf9a 100644
--- a/src/librustdoc/html/static/main.js
+++ b/src/librustdoc/html/static/main.js
@@ -106,6 +106,30 @@
         return (elem.offsetParent === null)
     }
 
+    function showSidebar() {
+        var elems = document.getElementsByClassName("sidebar-elems")[0];
+        if (elems) {
+            elems.style.display = "block";
+        }
+        var sidebar = document.getElementsByClassName('sidebar')[0];
+        sidebar.style.position = 'fixed';
+        sidebar.style.width = '100%';
+        sidebar.style.marginLeft = '0';
+        document.getElementsByTagName("body")[0].style.marginTop = '45px';
+    }
+
+    function hideSidebar() {
+        var elems = document.getElementsByClassName("sidebar-elems")[0];
+        if (elems) {
+            elems.style.display = "";
+        }
+        var sidebar = document.getElementsByClassName('sidebar')[0];
+        sidebar.style.position = '';
+        sidebar.style.width = '';
+        sidebar.style.marginLeft = '';
+        document.getElementsByTagName("body")[0].style.marginTop = '';
+    }
+
     // used for special search precedence
     var TY_PRIMITIVE = itemTypes.indexOf("primitive");
 
@@ -130,6 +154,8 @@
     }
 
     function highlightSourceLines(ev) {
+        // If we're in mobile mode, we should add the sidebar in any case.
+        hideSidebar();
         var search = document.getElementById("search");
         var i, from, to, match = window.location.hash.match(/^#?(\d+)(?:-(\d+))?$/);
         if (match) {
@@ -1459,7 +1485,7 @@
 
     // delayed sidebar rendering.
     function initSidebarItems(items) {
-        var sidebar = document.getElementsByClassName('sidebar')[0];
+        var sidebar = document.getElementsByClassName('sidebar-elems')[0];
         var current = window.sidebarCurrent;
 
         function block(shortty, longty) {
@@ -1829,6 +1855,22 @@
         removeClass(search, "hidden");
         search.innerHTML = '<h3 style="text-align: center;">Loading search results...</h3>';
     }
+
+    var sidebar_menu = document.getElementsByClassName("sidebar-menu")[0];
+    if (sidebar_menu) {
+        sidebar_menu.onclick = function() {
+            var sidebar = document.getElementsByClassName('sidebar')[0];
+            if (sidebar.style.position === "fixed") {
+                hideSidebar();
+            } else {
+                showSidebar();
+            }
+        };
+    }
+
+    window.onresize = function() {
+        hideSidebar();
+    };
 }());
 
 // Sets the focus on the search bar at the top of the page
diff --git a/src/librustdoc/html/static/rustdoc.css b/src/librustdoc/html/static/rustdoc.css
index f32252b726c..b342df6a464 100644
--- a/src/librustdoc/html/static/rustdoc.css
+++ b/src/librustdoc/html/static/rustdoc.css
@@ -208,7 +208,7 @@ nav.sub {
 .sidebar .version {
 	font-size: 15px;
 	text-align: center;
-	border-bottom: #DDDDDD 1px solid;
+	border-bottom: 1px solid;
 	overflow-wrap: break-word;
 	word-wrap: break-word; /* deprecated */
 	word-break: break-word; /* Chrome, non-standard */
@@ -247,8 +247,8 @@ nav.sub {
 }
 
 .sidebar-title {
-	border-top: 1px solid #777;
-	border-bottom: 1px solid #777;
+	border-top: 1px solid;
+	border-bottom: 1px solid;
 	text-align: center;
 	font-size: 17px;
 	margin-bottom: 5px;
@@ -263,6 +263,10 @@ nav.sub {
 	width: 100%;
 }
 
+.sidebar-menu {
+	display: none;
+}
+
 .content {
 	padding: 15px 0;
 }
@@ -364,7 +368,6 @@ h4 > code, h3 > code, .invisible > code {
 }
 
 .invisible {
-	background: rgba(0, 0, 0, 0);
 	width: 100%;
 	display: inline-block;
 }
@@ -444,7 +447,6 @@ h4 > code, h3 > code, .invisible > code {
 .content .fn .where,
 .content .where.fmt-newline {
 	display: block;
-	color: #4E4C4C;
 	font-size: 0.8em;
 }
 
@@ -538,7 +540,6 @@ a {
 }
 
 .search-input:focus {
-	border-color: #66afe9;
 	border-radius: 2px;
 	border: 0;
 	outline: 0;
@@ -560,7 +561,8 @@ a {
 .content .search-results td:first-child a { padding-right: 10px; }
 
 tr.result span.primitive::after {
-	content: ' (primitive type)'; font-style: italic; color: black;
+	content: ' (primitive type)';
+	font-style: italic;
 }
 
 body.blur > :not(#help) {
@@ -697,7 +699,6 @@ a.test-arrow:hover{
 	font-weight: 300;
 	position: absolute;
 	left: -23px;
-	color: #999;
 	top: 0;
 }
 
@@ -823,7 +824,7 @@ span.since {
 		position: static;
 	}
 
-	.sidebar .location {
+	.sidebar > .location {
 		float: right;
 		margin: 0px;
 		margin-top: 2px;
@@ -843,16 +844,33 @@ span.since {
 		margin-top: 5px;
 		margin-bottom: 5px;
 		float: left;
+		margin-left: 50px;
 	}
 
-	nav.sub {
-		margin: 0 auto;
+	.sidebar-menu {
+		position: absolute;
+		font-size: 2rem;
+		cursor: pointer;
+		margin-top: 2px;
+		display: block;
 	}
 
-	.sidebar .block {
+	.sidebar-elems {
+		background-color: #F1F1F1;
+		position: fixed;
+		z-index: 1;
+		left: 0;
+		top: 45px;
+		bottom: 0;
+		overflow-y: auto;
+		border-right: 1px solid #000;
 		display: none;
 	}
 
+	nav.sub {
+		margin: 0 auto;
+	}
+
 	.content {
 		margin-left: 0px;
 	}
@@ -904,8 +922,6 @@ span.since {
 .tooltip .tooltiptext {
 	width: 120px;
 	display: none;
-	background-color: black;
-	color: #fff;
 	text-align: center;
 	padding: 5px 3px;
 	border-radius: 6px;
@@ -927,13 +943,10 @@ span.since {
 	margin-top: -5px;
 	border-width: 5px;
 	border-style: solid;
-	border-color: transparent black transparent transparent;
 }
 
 .important-traits .tooltip .tooltiptext {
-	background-color: white;
-	color: black;
-	border: 1px solid #000;
+	border: 1px solid;
 }
 
 pre.rust {
@@ -953,22 +966,21 @@ pre.rust {
 	float: left;
 	width: 33.3%;
 	text-align: center;
-	border-bottom: 1px solid #ccc;
+	border-bottom: 1px solid;
 	font-size: 18px;
 	cursor: pointer;
 }
 
 #titles > div.selected {
-	border-bottom: 3px solid #0078ee;
+	border-bottom: 3px solid;
 }
 
 #titles > div:hover {
-	border-bottom: 3px solid #0089ff;
+	border-bottom: 3px solid;
 }
 
 #titles > div > div.count {
 	display: inline-block;
-	color: #888;
 	font-size: 16px;
 }
 
@@ -987,7 +999,6 @@ h4 > .important-traits {
 	position: fixed;
 	width: 100vw;
 	height: 100vh;
-	background-color: rgba(0,0,0,0.3);
 	z-index: 10000;
 	top: 0;
 	left: 0;
@@ -997,13 +1008,12 @@ h4 > .important-traits {
 	display: block;
 	max-width: 60%;
 	min-width: 200px;
-	background-color: #eee;
 	padding: 8px;
 	top: 40%;
 	position: absolute;
 	left: 50%;
 	transform: translate(-50%, -40%);
-	border: 1px solid #999;
+	border: 1px solid;
 	border-radius: 4px;
 	border-top-right-radius: 0;
 }
@@ -1030,35 +1040,24 @@ h3.important {
 	right: -25px;
 	top: -1px;
 	font-size: 18px;
-	background-color: #eee;
 	width: 25px;
 	padding-right: 2px;
 	border-top-right-radius: 5px;
 	border-bottom-right-radius: 5px;
 	text-align: center;
-	border: 1px solid #999;
+	border: 1px solid;
 	border-right: 0;
 	cursor: pointer;
 }
 
-.modal-content > .close:hover {
-	background-color: #ff1f1f;
-	color: white;
-}
-
 .modal-content > .whiter {
 	height: 25px;
 	position: absolute;
 	width: 3px;
-	background-color: #eee;
 	right: -2px;
 	top: 0px;
 }
 
-.modal-content > .close:hover + .whiter {
-	background-color: #ff1f1f;
-}
-
 #main > div.important-traits {
 	position: absolute;
 	left: -24px;
diff --git a/src/librustdoc/html/static/styles/main.css b/src/librustdoc/html/static/styles/main.css
index cb19034bf06..5cace837a55 100644
--- a/src/librustdoc/html/static/styles/main.css
+++ b/src/librustdoc/html/static/styles/main.css
@@ -31,6 +31,10 @@ h2, h3:not(.impl):not(.method):not(.type):not(.tymethod), h4:not(.method):not(.t
 	background-color: white;
 }
 
+.invisible {
+	background: rgba(0, 0, 0, 0);
+}
+
 .docblock code, .docblock-short code {
 	background-color: #F5F5F5;
 }
@@ -56,6 +60,15 @@ pre {
 	color: #333;
 }
 
+.sidebar .version {
+	border-bottom-color: #DDD;
+}
+
+.sidebar-title {
+	border-top-color: #777;
+	border-bottom-color: #777;
+}
+
 .block a:hover {
 	background: #F5F5F5;
 }
@@ -89,6 +102,12 @@ pre {
 	background: #FDFFD3;
 }
 
+.content .method .where,
+.content .fn .where,
+.content .where.fmt-newline {
+	color: #4E4C4C;
+}
+
 .content .highlighted {
 	color: #000 !important;
 	background-color: #ccc;
@@ -152,12 +171,20 @@ a.test-arrow {
 	color: #f5f5f5;
 }
 
+.collapse-toggle {
+	color: #999;
+}
+
 .search-input {
 	color: #555;
 	box-shadow: 0 0 0 1px #e0e0e0, 0 0 0 2px transparent;
 	background-color: white;
 }
 
+.search-input:focus {
+	border-color: #66afe9;
+}
+
 .stab.unstable { background: #FFF5D6; border-color: #FFC600; }
 .stab.deprecated { background: #F3DFFF; border-color: #7F0087; }
 .stab.portability { background: #C4ECFF; border-color: #7BA5DB; }
@@ -176,6 +203,10 @@ a.test-arrow {
 	color: grey;
 }
 
+tr.result span.primitive::after {
+	color: black;
+}
+
 .line-numbers :target { background-color: transparent; }
 
 /* Code highlighting */
@@ -241,3 +272,61 @@ pre.ignore:hover, .information:hover + pre.ignore {
 .search-failed > a {
 	color: #0089ff;
 }
+
+.tooltip .tooltiptext {
+	background-color: black;
+	color: #fff;
+}
+
+.tooltip .tooltiptext::after {
+	border-color: transparent black transparent transparent;
+}
+
+.important-traits .tooltip .tooltiptext {
+	background-color: white;
+	color: black;
+	border-color: black;
+}
+
+#titles > div {
+	border-bottom-color:  #ccc;
+}
+
+#titles > div.selected {
+	border-bottom-color: #0078ee;
+}
+
+#titles > div:hover {
+	border-bottom-color: #0089ff;
+}
+
+#titles > div > div.count {
+	color: #888;
+}
+
+.modal {
+	background-color: rgba(0,0,0,0.3);
+}
+
+.modal-content {
+	background-color: #eee;
+	border-color: #999;
+}
+
+.modal-content > .close {
+	background-color: #eee;
+	border-color: #999;
+}
+
+.modal-content > .close:hover {
+	background-color: #ff1f1f;
+	color: white;
+}
+
+.modal-content > .whiter {
+	background-color: #eee;
+}
+
+.modal-content > .close:hover + .whiter {
+	background-color: #ff1f1f;
+}
diff --git a/src/libstd/macros.rs b/src/libstd/macros.rs
index b36473d9b75..de46fedaebb 100644
--- a/src/libstd/macros.rs
+++ b/src/libstd/macros.rs
@@ -631,7 +631,7 @@ pub mod builtin {
     #[macro_export]
     macro_rules! module_path { () => ({ /* compiler built-in */ }) }
 
-    /// Boolean evaluation of configuration flags.
+    /// Boolean evaluation of configuration flags, at compile-time.
     ///
     /// In addition to the `#[cfg]` attribute, this macro is provided to allow
     /// boolean expression evaluation of configuration flags. This frequently